Automatic feed drill



Jan. 4, 1938. 'N. o. GROSSER 0 AUTOMATIC FEED DRILL Filed July 28, 1936Patented Jan. 4, 1938 othe AUTOMATIC FEED DRILL Nelson 0. Grosser,

Prince Albert, Saskatchewan,"

Canada Application July 28, 1936, Serial No. 93,110

1 Claim. (01. 77- -34) This invention relates to improvements inautomatic feed drills, and an object of the invention is to provide adevice of the character herein "described which will feed the bitforwardly as the drill is rotated but which will prevent the bitfrom'exerting excessive pressure against the work being executed; whichpressure might damage the work or destroy the bit.

. A further object of the invention is to provide a device of thecharacter herein described in which the feeding mechanism urges therotating shank forwardly by means of a nut threadably mounted thereon;the nut being normally maintained in a stationary position by a frictiondisc bearable thereagainst. I V .A further object of my invention is toprovide a device of the character herein described in which the normaland maximum pressures exerted by thebit on the work may be adjusted. V

A still further object of my invention is to provide a device of thecharacter herein described which is simple and rugged in construction,is economical to manufacture and will not easily become out of order. 7I

With the above more important objects in view and such other minorobjects as may appear as the specification proceeds, my inventionconsists essentially in the arrangement and construction of parts all ashereinafter more particularly described, reference being had to theaccompanying drawing, in which:-'-

Fig. 1 illustrates a side elevation of my improved type of automaticdrill.

Fig. 2 is a front sectional elevation taken on the line 22 Figure 1.

Fig. 3 is a sectional detail view taken on the line 33 Figure 2.

In the drawing like characters of reference indicate corresponding partsin the different figures.

This invention consistsof a bed or casting I to either side of which areattached a pair of mutually converging plates 2 which are attached tothe bed by bolts 3 or by any other convenient method, An aperture 4having a configuration as clearly shown in Fig.1 is cut in the upperends of the plates and the arms 5 and 6 on either side thereof, areformed to receive bearings I and 8 which are integrally attachedthereto. It should be noted that the rear bearing designated by thenumeral 8 is extended forwardly and is threaded as at 9 for a purposepresently to be explained. Mounted within these bearings is a centralshank I provided at the forward end with a cylindrical clutch H having aset screw I2 extending through collar extends a short sleeve l9.

the face of the sleeve]!!! atall times.

the wall thereof. The opposite end of'the shank is formed with acircular flange it to which is attached by means of bolts i l, amanually operable crank I5.

Substantially centrally disposed along the length of the shank is .athreaded'portion l6 designed to receive an internally tapped nut orcollar I l, the forward face 18 of which is essentially a'plane surface.From the opposite side of the Mounted upon the threaded portion 9 of thesleeve 8 is an adjustable nut 29 and bearing against the face of thesleeve 59 is a small thrust bearing 2! which is freely mounted upon theshaft it. interposed between this bearing and the nut Zt is acompression spring 32 which is adapted to maintain the bearing incontact with Extending around. and freely mounted uponthe inner end ofthe sleeve l isa friction. disc 23 to the face of which is attached'alayer 24' offriction material such as leather or any other suitablesubstance. If desired, however, the friction layer24 may be dispensedwith, as it has been found that the device will operateverysatisfac 25torily when utilizing the frictional force developed between theopposing faces of the collar I1 and the disc 23. The lower end of thedisc 23, it should be mentioned, is provided with a forwardly extendingintegral lug 25 having a c0nfiguration as most clearly shown in Fig. 2which is designed to be received between the inner faces of the sideplates 2 and thus to prevent rotation of the friction disc, but to allowshifting movement thereof on the bearing 1.

Mounted on one side of the bearing 1 is an 'angulated lever arm 26 whichis pivoted at 21.

The inner end of this arm is provided with a short finger 28 which isbearable against the forward surface of the disc 23. It should here benoted that when the lever is raised to the position shown in phantomlines, the force of the spring 22 will urge the collar I1 forwardly toultimately bear against the inner end of the bearing 1 upon which thefriction disc is mounted. When this occurs, there is no pressure betweenthe 'layer 24 and the collarand consequently, no friction therebetween.However, lowering the lever to the position shown in full lines willcause the finger 28 to engage with the friction disc and 5 force thefriction layer 24 against the face of the collar I I, thus producing aconsiderable frictional retarding force therebetween when the shank I0is rotated.

Extending through the circular passage 29,

Within the bed I of the device, is a sleeve 30 which is held firmly inposition by a bolt 3| passing therethrough. Into the forward end of thissleeve is inserted a turned arm 32 on the upper end of which is afiixedany conventional type of drill shoe or table 33.

In order to adjust the position of the table a lever 34 is threadablyreceived within a boss 35 upon the side of the sleeve 30 and acts in themanner of a set screw to maintain the arm 32 in any desired position.Although in the drawing accompanying this application only a singlelever 34 has been illustrated, it has been found somewhat moreconvenient to have a second lever attached to the sleeve 35 by a bossdiametrically opposed to the boss 35. This arrangement permits theoperator of the device to adjust the table 33 from either side of thedrill.

The structure of my improved type of drill having been given, its modeof operation will now be presented.

If the lever 26 is raised to the position shown in broken lines and theshank Ill is rotated by means of the crank l 5, it will not moveforwardly for the collar I9 will simply rotate with the shank as thereis not sufiicient friction between the collar and the inner end of thebearing 1 to retard this member. If, however, the lever 26 is loweredand the friction material 24 is forced against the face of the collar,it will cease rotating and the shank II] will thread through the centralportion thereof, thus advancing the It will therefore be seen that whendrilling, the device will adjust itself to materials of varioushardnesses.

The nut 20, it should be mentioned, is used to adjust the pressure ofthe spring 22 against thethrust bearing and thus the pressure of thecollar i? upon the friction material 24 as the frictional force betweenthe two elements determines the pressure that the bit will exert, the

nut 29 is therefore used to adjust the normal pressure of the bitagainst the work being executed.

From the foregoing, it will now be obvious that I have invented anextremely useful and compact type of drill, which prevents continualbreaking of bits when used to drill hard material, is simple inconstruction, and will not easily become out of order.

Since various modifications can be made in the above invention, and manyapparently widely different embodiments of same made within the scope ofthe claim without departing from the spirit and scope thereof, it isintended that all matter contained in the accompanying specificationshall be interpreted as illustrative only and not in a limiting senseand I desire only such limitations placed thereon as are specificallyexpressed in the accompanying claim.

What I claim as my invention is:

A drilling machine comprising in combination,

a framework, a pair of bearings mounted thereon,

a rotatable element threadably received upon one of said bearings, arotatable shaft mounted within said bearings, a collar threadablysecured upon said shaft, a spring member engageable with said elementand adapted to exert pressure against said collar, a friction discslidably mounted upon the other of said bearings, a lug protrudingtherefrom adapted to engage with a portion of said framework to preventrotation of said disc, manually operable lever means for urging saiddisc into engagement with said collar, said lever means being adaptedwhen in a selected position to permit complete disengagement of saiddisc from said collar.

NELSON O. GROSSER.

